This invention relates to orthodontic headgear, generally termed "nightbrace" or "face bow", and more particularly to an improved orthodontic headgear which provides intrusion or extrusion forces as well as the conventional rearwardly directed forces.
Conventional face bows comprise an inner bow member, made of wire, which engages buccal tubes which are fixed on respective teeth on opposite sides of the mouth. An outer bow, of wire, is connected to the inner bow at a forward end thereof and extends around the outside of the patient's face and engages an elastic or other biassing arrangement which extends around the back of the head of the patient. Typical face bows are illustrated, for example, in U.S. Pat. Nos. 4,087,915; 3,337,958; and 3,303,566.
The object of the present invention is to provide an orthodontic headgear or face bow which, in addition to the conventional rearwardly directed forces, provides intrusion or extrusion forces to the teeth to which the inner bow is attached in a simple and controllable manner.
It is a further object of the invention to provide such a face bow with inner and outer bows which are movably connected relative to each other and which has conveniently arranged biassing means coupled to the inner and outer bows.